Further, many publishers are not showing a lot of foresight in how they integrate video and other features in the electronic textbooks. . . . multimedia learning is more complex than one would think. Videos, illustrative simulations, hyperlinked definitions–all these can aid comprehension OR hurt comprehension, depending on sometimes subtle differences in how they are placed in the text, the specifics of the visuals, the individual abilities of readers, and so on.

What works for e-books — putting the same words in a new format — may not work for e-texts, Willingham writes. “Textbooks have different content, different structure, and they are read for different purposes.”